Equalizers for layered modulated and other signals

Abstract

A method and apparatus for equalizing digital data signals is disclosed. The method comprises the steps of demodulating and decoding an input signal having input data to produce a data output, remodulating the data output to produce a training sequence including an idealized input signal, wherein the training sequence is comprised of adjacent symbols in the input data, and generating equalizer parameters from the training sequence. The apparatus comprises a demodulator (for demodulating an input signal to produce a data output), a modulator communicatively coupled to the demodulator (for remodulating the data output to produce a training sequence including an idealized input signal wherein the training sequence is comprised of adjacent symbols in the input data), and a parameter generation module communicatively coupled to the modulator (for generating equalizer parameters from the training sequence).

1. A method of equalizing digital data signals, comprising:
 demodulating an input signal having input data; 
 decoding the demodulated input signal to produce a data output; 
 re-encoding the data output; 
 remodulating the re-encoded data output to produce a training sequence, wherein the training sequence is comprised of adjacent symbols in the input data; and 
 generating equalizer parameters from the training sequence. 
 
     
     
       2. The method of  claim 1 , wherein the step of generating equalizer parameters comprises comparing the training sequence with the input signal to determine channel distortion. 
     
     
       3. The method of  claim 2 , wherein the step of generating equalizer parameters comprises subtracting the adjacent symbols from the input signal to reproduce channel impairments, wherein the channel impairments are subtracted from the input signal for equalization. 
     
     
       4. The method of  claim 3 , wherein the channel impairments comprise inter-symbol interference. 
     
     
       5. The method of  claim 1 , wherein the step of generating equalizer parameters from the remodulated data output comprises:
 buffering the input signal; and 
 comparing the buffered input signal to the training sequence to produce the equalizer parameters. 
 
     
     
       6. An apparatus for equalizing digital data signals, comprising:
 means for demodulating an input signal having input data; 
 means for decoding the input signal to produce a data output; 
 means for re-encoding the data output; 
 means for remodulating the re-encoded data output to produce a training sequence, wherein the training sequence is comprised of adjacent symbols in the input data; and 
 means for generating equalizer parameters from the training sequence. 
 
     
     
       7. The apparatus of  claim 6 , wherein the means for generating equalizer parameters comprises means for comparing the training sequence with the input signal to determine channel distortion. 
     
     
       8. The apparatus of  claim 7 , wherein the means for generating equalizer parameters comprises means for subtracting the adjacent symbols from the input signal to reproduce channel impairments, wherein the channel impairments are subtracted from the input signal for equalization. 
     
     
       9. The apparatus of  claim 8 , wherein the channel impairments comprise inter-symbol interference. 
     
     
       10. The apparatus of  claim 6 , wherein the means for generating equalizer parameters from the remodulated data output comprises:
 means for buffering the input signal; and 
 means for comparing the buffered input signal to the training sequence to produce the equalizer parameters. 
 
     
     
       11. An apparatus for equalizing digital data signals comprising:
 a demodulator for demodulating an input signal; 
 a decoder for decoding the input signal to produce a data output; 
 a re-encoder for re-encoding the data output; 
 a modulator, communicatively coupled to the demodulator, for remodulating the re-encoded data output to produce a training sequence, wherein the training sequence is comprised of adjacent symbols in the input data; and 
 a parameter generation module, communicatively coupled to the modulator, for generating equalizer parameters from the training sequence. 
 
     
     
       12. The apparatus of  claim 11 , wherein the parameter generation module compares the training sequence with the input signal to determine channel distortion. 
     
     
       13. The apparatus of  claim 12 , wherein the parameter generation module subtracts the adjacent symbols from the input signal to reproduce channel impairments, wherein the channel impairments are subtracted from the input signal for equalization. 
     
     
       14. The apparatus of  claim 13 , wherein the channel impairments comprise inter-symbol interference. 
     
     
       15. The apparatus of  claim 11 , wherein the parameter generation module comprises:
 means for buffering the input signal; and 
 means for comparing the buffered input signal to the training sequence to produce the equalizer parameters. 
 
     
     
       16. A method of equalizing digital data signals, comprising:
 demodulating an input signal having input data to produce a data output; 
 remodulating the data output to produce a training sequence, wherein the training sequence is comprised of adjacent symbols in the input data; and 
 generating equalizer parameters from the training sequence, comprising the step of comparing the training sequence with the input signal to determine channel distortion. 
 
     
     
       17. The method of  claim 16 , wherein the step of generating equalizer parameters comprises subtracting the adjacent symbols from the input signal to reproduce channel impairments, wherein the channel impairments are subtracted from the input signal for equalization. 
     
     
       18. The method of  claim 17 , wherein the channel impairments comprise inter-symbol interference. 
     
     
       19. The method of  claim 16 , wherein the step of generating equalizer parameters from the remodulated data output comprises:
 buffering the input signal; and 
 comparing the buffered input signal to the training sequence to produce the equalizer parameters. 
 
     
     
       20. A method of equalizing digital data signals, comprising:
 demodulating an input signal having input data to produce a data output; 
 remodulating the data output to produce a training sequence, wherein the training sequence is comprised of adjacent symbols in the input data; and 
 generating equalizer parameters from the training sequence, comprising the steps of:
 buffering the input signal; and 
 comparing the buffered input signal to the training sequence to produce the equalizer parameters. 
 
 
     
     
       21. An apparatus for equalizing digital data signals, comprising:
 means for demodulating an input signal having input data to produce a data output; 
 means for remodulating the data output to produce a training sequence, wherein the training sequence is comprised of adjacent symbols in the input data; and 
 means for generating equalizer parameters from the training sequence, comprising means for comparing the training sequence with the input signal to determine channel distortion. 
 
     
     
       22. The apparatus of  claim 21 , wherein the means for generating equalizer parameters comprises means for subtracting the adjacent symbols from the input signal to reproduce channel impairments, wherein the channel impairments are subtracted from the input signal for equalization. 
     
     
       23. The apparatus of  claim 22 , wherein the channel impairments comprise inter-symbol interference. 
     
     
       24. The apparatus of  claim 21 , wherein the means for generating equalizer parameters from the remodulated data output comprises:
 means for buffering the input signal; and 
 means for comparing the buffered input signal to the training sequence to produce the equalizer parameters. 
 
     
     
       25. An apparatus for equalizing digital data signals, comprising:
 means for demodulating an input signal having input data to produce a data output; 
 means for remodulating the data output to produce a training sequence, wherein the training sequence is comprised of adjacent symbols in the input data; and 
 means for generating equalizer parameters from the training sequence, comprising:
 means for buffering the input signal; and 
 means for comparing the buffered input signal to the training sequence to produce the equalizer parameters. 
 
 
     
     
       26. An apparatus for equalizing digital data signals comprising:
 a demodulator for demodulating an input signal to produce a data output; 
 a modulator, communicatively coupled to the demodulator, for remodulating the data output to produce a training sequence, wherein the training sequence is comprised of adjacent symbols in the input data; and 
 a parameter generation module, communicatively coupled to the modulator, for generating equalizer parameters from the training sequence, wherein the parameter generation module compares the training sequence with the input signal to determine channel distortion. 
 
     
     
       27. The apparatus of  claim 26 , wherein the parameter generation module subtracts the adjacent symbols from the input signal to reproduce channel impairments, wherein the channel impairments are subtracted from the input signal for equalization. 
     
     
       28. The apparatus of  claim 27 , wherein the channel impairments comprise inter-symbol interference. 
     
     
       29. The apparatus of  claim 26 , wherein the parameter generation module comprises:
 means for buffering the input signal; and 
 means for comparing the buffered input signal to the training sequence to produce the equalizer parameters. 
 
     
     
       30. An apparatus for equalizing digital data signals comprising:
 a demodulator for demodulating an input signal to produce a data output; 
 a modulator, communicatively coupled to the demodulator, for remodulating the data output to produce a training sequence, wherein the training sequence is comprised of adjacent symbols in the input data; and 
 a parameter generation module, communicatively coupled to the modulator, for generating equalizer parameters from the training sequence, comprising:
 means for buffering the input signal; and 
 means for comparing the buffered input signal to the training sequence to produce the equalizer parameters.